Method and system for component wear monitoring

ABSTRACT

A monitoring system includes a fastener. A sensor is coupled to the fastener. A circuit board is electrically coupled to the sensor. An antenna electrically coupled to the circuit board.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/967,932, filed on May 1, 2018. U.S. application Ser. No. 15/967,932claims priority to U.S. Provisional Patent Application No. 62/492,361,filed on May 1, 2017. U.S. patent application Ser. No. 15/967,932 andU.S. Provisional Patent Application No. 62/492,361 are herebyincorporated by reference.

BACKGROUND Technical Field

The present disclosure is directed to a method and system for monitoringthe forces, temperatures, and movements of fasteners, rollers, and wearsurfaces and transmitting that information to a data acquisition system.

Description of the Related Art

In the current art several different methods have been developed in aneffort to determine the integrity of a fastener such as, for example, abolt. In underground roof bolting, for example, the conventionalapproach for determining bolt integrity is the pull-out test. Thepull-out test is a time-consuming and destructive process. Therefore,the necessity to develop non-destructive test methods that can be usedto determine the reliability of the rock bolt in-situ is urgent.Developments in sensing materials have provided several potentialsensing methods. Piezoelectric materials and fiber-optic sensors arecurrently two of the most widely adopted sensing techniques.Piezoelectric transducers require proper protection and obtainingsignals from sensors can be problematic due to cabling issues.Fiber-optic sensors are useful in monitoring within areas with highelectromagnetic interference and high temperatures but may not providethe information provided by piezoelectric sensors.

SUMMARY

In one aspect, the present disclosure relates to a monitoring system.The monitoring system includes a fastener. A sensor is coupled to thefastener. A circuit board is electrically coupled to the sensor. Anantenna electrically coupled to the circuit board.

In another aspect, the present disclosure relates to a roller wearsensor. The roller wear sensor includes a bearing assembly. A sensor isdisposed with the bearing assembly. An antenna is electrically coupledto the sensor. A power source is electrically coupled to the antenna.

In another aspect, the present disclosure relates to a wear monitoringsystem. The wear monitoring system includes a plurality of wear pads. Asensor is disposed within the wear pad. An antenna is electricallycoupled to the sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a single-sided embodiment of the remote recessed reflectorantenna;

FIG. 2A is a section view of a fastener showing sensors, a processor anda remote recessed reflector antenna embedded therein;

FIG. 2B is an exploded perspective view of the fastener of FIG. 2A;

FIG. 2C is a section view of a small diameter fastener showing sensors,a processor and an antenna mounted thereon;

FIG. 2D is an exploded perspective view of the small diameter fastenerof FIG. 2C;

FIG. 3A is a section view of a nut having sensors, a processor and aremote recessed reflector antenna mounted therein;

FIG. 3B is an exploded perspective view of the nut of FIG. 3A; FIG. 4 isa section view of a roof bolt engaged with a load-bearing nut that showssensors, a processor and a remote recessed reflector antenna mountedtherein;

FIG. 5 is a section view of a roof bolt engaged with a passive nut thatshows sensors, a processor and a remote recessed reflector antennamounted therein;

FIG. 6 is a perspective section view of a ball mill liner havingmounting bolts engaged with a load-bearing nut that shows sensors, aprocessor and a remote recessed reflector antenna mounted therein;

FIG. 7 is an exploded perspective view of a ball mill liner havingmounting bolts engaged with a passive nut that shows sensors, aprocessor and a remote recessed reflector antenna mounted therein;

FIG. 8 is a flow chart of a typical mesh network topology;

FIG. 10 is a perspective view of a roof bolt monitoring system withpersonnel integration;

FIG. 9 is a perspective view of a plurality of wireless bolt monitoringsystems in mesh network communication;

FIG. 11A is a perspective view of the electronics of a roller conditionmonitoring system;

FIG. 11B is a perspective view of the electronics of a roller conditionmonitoring system disposed in a housing;

FIG. 11C is a perspective view of a conveyor roller trough;

FIG. 12 is a schematic of a redundant resistor wear ladder circuit;

FIG. 13A is a perspective view of a conveyor chute;

FIG. 13B is an exploded perspective view of a conveyor pad wearmonitoring system;

FIG. 13C is an alternative exploded perspective view of a conveyor padwear monitoring system;

FIG. 13D is an exploded perspective view of an alternative conveyor padwear monitoring system; and

FIG. 13E is an alternative exploded perspective view of an alternativeconveyor pad wear monitoring system;

DETAILED DESCRIPTION

An example embodiment of an antenna with recessed reflector is shown inFIG. 1. The antenna 101, series and shunt tuning components 102, andcable connector 103 are mounted on a small circuit board (“PCB”) 104that is positioned in the antenna cavity 105 with two mounting holes 107aligned with threaded screw holes 106 in the bottom of the antennacavity 105. The bottom sides of the two screw holes 106 in the circuitboard 104 have exposed annular rings 108 that are conductively bonded toa steel surface of the bottom of the cavity 105 using an electricallyconductive compound. This conductive joint between the grounded PCB 104annular rings 108 extends the PCB 104 ground plane into the steelchassis 109. This overall ground plane acts as the reflector for theantenna. The current means of mounting these types of antennas is on theedges of flat corner surface reflectors. Mounting the antenna 101 onflat surface corner reflectors is not possible on flat surfaces becausethe surfaces 110 are exposed to a harsh environment (the antenna 101would eventually be destroyed). Recessing the antenna 101 into thesurface prevents it from being damaged or scraped off the surface ontraveled, wear, or aerodynamic surfaces.

The antenna 101 and the PCB 104 are further protected with a cover 111formed out of a material (such as PTFE) that fills the cavity 105 infront of the antenna 101 and which is attached by means of two screws112. Connectors 103 are attached to RF cables 113. RF cables 113 carrysignals to and from the transceiver and the processing circuit board114. Dimensions 115 of the cavity 105 allow the radiation pattern 116 tobe modified by altering these dimensions 115, when practical. This setof cavity 105 dimensions 115 is specific to this example and mayobviously be altered, as required, for similar embodiments of thisdisclosure. Recessing the antenna 101 and changing the dimensions of the115 cavity 105 changes the radiation characteristics from anomnidirectional configuration that is characteristic of radiationreflected off of a horn antenna. These changes will make the antenna 101beam operate in a directional pattern.

FIG. 2A is a section view of a fastener 201 such as, for example, a boltwith an embedded monitoring system. The fastener 201 acts as a fastenerof a first object 202 to a second object 203. The center of the fastener201 has a bore 204 containing a tension sensor 205 therein. The tensionsensor 205 is in electrical communication with a printed circuit board206 that has additional sensors thereon. The printed circuit board 206is in electrical communication with the remote recessed reflectorantenna 207 shown in FIG. 1. The electrical components are powered by abattery 208. FIG. 2B is an exploded perspective view of the system shownin FIG. 2A.

FIG. 2C is a section view of a small diameter fastener 209 having amonitoring system mounted thereon. The small diameter fastener 209 is afastener of a first object 210 and a second object 211. The smalldiameter fastener 209 has a washer 212 having sensors 213 mountedthereon. The washer 212 is connected to a donut-shaped printed circuitboard 214 with antenna 215 via screws 216 that are disposed withinspacers 217 such that the head of the fastener 209 has clearance throughthe center of the donut-shaped printed circuit board 214. Thedonut-shaped printed circuit board 214 is powered by a battery 218 thatis fixed to a battery printed circuit board 219. FIG. 2D is an explodedperspective view of the system shown in FIG. 2C.

FIG. 3A is a section view of an embedded monitoring system for a nut301. The nut 301 has an optional embedded strain sensor 302 that is inelectrical communication with a printed circuit board 303 with sensors.The strain sensor 302 is only necessary in a load-bearing embodiment ofthe nut 301. The printed circuit board 303 is in electricalcommunication with the remote recessed reflector antenna 304 of FIG. 3A.The system of FIG. 3A is powered by a battery 305. FIG. 3B is anexploded perspective view of the system of FIG. 3A.

FIG. 4 is a perspective view of a load-bearing embodiment 401 of thesystem 301 shown in FIGS. 3A-3B. The load-bearing embodiment 401 isattached to a roof bolt 402 to serve as an exemplary application of theload-bearing embodiment 401 of the system 301 in FIGS. 3A-3B. A roofbolt 402 is engaged with strata 403 such that the bolt 402 is in tensionwhen the load-bearing embodiment 401 of the system 301 shown in FIG. 3Ais threaded onto the bolt 402 and compressed against the bearing plate404. Tension in the bolt 402 is related to compression in theload-bearing embodiment 401 of the system 301, which is monitored fromthe strain sensor 302 shown in FIG. 3A. Vibration may also be monitoredby the sensors 117 on the printed circuit board 114. Changes in thecharacteristics of vibration, such as amplitude and frequency, inducedby normal activities such as mining can be used to make inferences aboutthe integrity of the bolt 402.

FIG. 5 is a perspective view of a passive embodiment 501 of the system301 shown in FIGS. 3A-3B. In the present disclosure, “passive” refers toa system that is not load-bearing and has no need for strain sensors302. A roof bolt 502 is engaged with roof strata 503 such that the bolt502 is in tension when the conventional nut 504 is threaded onto thebolt 502 and compressed against the bearing plate 505. The passive,monitoring nut is threaded onto the roof bolt 502 after the conventionalnut 504 but is not threaded to a point that introduces compression tothe passive embodiment 501 of the system 301. Vibration is monitored bythe sensors 117 on the printed circuit board 114. Changes in thecharacteristics of vibration, such as amplitude and frequency, inducedby normal activities such as mining can be used to make inferences aboutthe integrity of the bolt 502.

FIG. 6 is a perspective view of a ball mill liner module having a liner601 secured to a mill wall 602 using mounting bolts 603 and aload-bearing embodiment 604 of the system 401. The load-bearingembodiment 604 of the system 301 shown in FIGS. 3A-3B is threaded ontoto the mounting bolts 603 and tightened against the outside of the millwall 602. As the mill liner 601 wears down, so do the mounting bolts603. Increased wear changes the length of the mounting bolts 603 whichchanges resonant frequency of the mounting bolt. Vibration induced bynormal mill operation excites vibration in the mounting bolts 603 so thefrequency of vibration can be monitored by the sensors in the system 604and wear can be inferred from this information. The strain sensor 302may also be used to monitor liner module integrity and infer wear. Forexample, if strain readings suddenly drop and remain at the decreasedreading for a period of time, it may be inferred that there is a loosecomponent in the mill liner module.

FIG. 7 is an exploded perspective view of a ball mill liner modulehaving a liner 701 secured to a mill wall 702 using mounting bolts 703and mounting nuts 705. The passive embodiment 704 of the system 301shown in FIGS. 3A-3B is threaded to the mounting bolts 703 over themounting nuts 705 outside of the mill wall 702. As the mill liner 701wears down, so do the mounting bolts 703. Increased wear changes thelength of the mounting bolts 703, which changes resonant frequency ofthe mounting bolt. Vibration induced by normal mill operation excitesvibration in the mounting bolts 703 so the frequency of vibration can bemonitored by the sensors in the passive embodiment 704 of the system 301shown in FIG. 3A and wear can be inferred from this information.

FIG. 8 shows basic network topology for a wireless networks. In thetopology, end nodes 801 transmit signals 803 to and receive signals 803from repeaters 802. Repeaters 802 transmit signals 803 to and receivesignals 803 from the director 804. In a typical embodiment, directors804 control the signal 803 paths between all of the devices in thenetwork. Repeaters 802 receive signals 803 from devices and replicatethem to other devices; and end nodes 801 send to and receive signals 803from repeaters 802 or directors 804.

FIG. 9 is a perspective view of a bolt monitoring system using meshnetwork communication. For the purposes of this patent application, FIG.9 represents, for example, development in an underground mine 901. Mostof the units of a roof bolt monitoring system act as end nodes 902 in amesh network. The information they gather is transmitted wirelesslyusing the remote recessed reflector antenna of FIG. 1 to a messengerunit 903. There may be one messenger unit 903 per several end nodes 902.The messenger node stores the information it has received and identifieswhich end node 902 the information was transmitted from. Periodically,the messenger node 903 wirelessly uploads the stored information to awireless data acquisition unit 904 that may be mobile or stationary. Thewireless data acquisition unit 904 may be powered by battery or may beattached to and powered by mobile mine equipment. All of the informationcollected from the wireless data acquisition unit 904 is finallyuploaded to a central data acquisition system 905 where information fromall the end nodes 902 can be accessed. The end nodes 902 are analogousto the end nodes 801 in FIG. 8. The messenger units 903 are analogous tothe repeaters in FIG. 8. The data acquisition systems 904 and 905 areanalogous to the directors 804 in FIG. 8.

The bolt monitoring system of FIG. 9 may be integrated with wearablecommunications technology, as illustrated in FIG. 10. In thisembodiment, the end nodes 1001 may transmit information to personnel1002 having wearable wireless communications technology 1003. Theinformation transmitted may include, for example, information about theintegrity of the roof in a working area 1104. In this example, movementof the roof may be detected by the end nodes 1001. The end nodes thentransmit to the wearable wireless communications system on personnel inthe working area. This may be accomplished by direct communicationbetween the end nodes 1001 and wearable system 1003 or by communicationbetween the end nodes 1001 and wearable system via a messenger unit1005. The wearable system 1003 is able to alert the personnel 1002 inthe area that working conditions are unsafe. The wearable system 1003 isalso able to transmit to the end nodes 1001, which may be used as a meshnetwork to relay the information throughout and outside the undergroundmine, to the messenger unit 1005, or directly to the data acquisitionunit 1006.

FIGS. 11A-11C illustrate a system for monitoring the condition ofconveyor rollers. The roller condition monitor 1101 may include anembedded assembly which is mounted on a molded frame 1102 and attachedto the inside of one end of a conveyor belt 1112, idler roller 1113, ora modular assembly that may be inserted and removed from the roller1103. FIG. 11A shows the printed circuit board with its componentsinstalled. FIG. 11B shows the circuit board assembly installed in themolded frame 1102. FIG. 11C shows a roller set with the conveyor belt1112. The monitor 1101 uses a thermal sensor that is built into thecommunication processor 1104 and a 3-axis accelerometer/gyro 1105 totrack: temperature, 3-axis acceleration and gyration of the roller.Monitored parameters are time stamped and passed to a centralizedcomputer through a network. The monitor is powered by batteries 1106.

Temperature monitoring is used to detect component wear. The ambienttemperature is determined by cross-correlating the readings from alltemperatures of rollers 1103 in the nearby vicinity. When thetemperature of a roller 1103 increases with respect to the ambienttemperatures of its neighboring rollers 1103, the increase may beattributed to a failing mechanical component such as a seized bearing,jammed drum, bent roller barrel 1107 or shaft 1108 or any other failedpart. Roller friction related failures are a common cause of fires inconveyor systems.

Vibrations monitoring is also used to detect failing mechanical rollerparts 1103. As parts wear, they begin to loosen and vibrate differentfrom new parts. Increased vibrations are an indication of roller 1103damage or wear.

Monitoring gyration rates of rollers 1103 with respect to other rollers1103 in the vicinity will help detect rollers 1103 that are turningslower than the belt speed. Ideally, all rollers 1103 will rotate at thespeed of the belt. When bearings seize, barrels 1107 jam againststructural components 1109, ends fail 1110, shafts 1108 bend, or otherfaults occur, rollers 1103 may be stalled, thus dragging against theconveyor belt 1112.

Parameters that are monitored inside the roller 1103 are stored in inthe communication processor 1104. At predetermined intervals, parametersare organized into data packets and transmitted out of the end of theroller 1103 through chip or printed circuit antennas 1111. One or moreantennas 1111 may be used for this communication. The use of multipleantennas 1111 allows multiple wireless radio energy paths to transmitaround blockages. Rollers 1103 that employ metal ends pass the radiosignal through a slot using a recessed reflector antenna 1111configuration. Rollers that employ non-metal ends may utilize either alevel surface mount or a recessed reflector antenna 1111 configuration.The use of two or more antennas 1111 may aide in keeping the rollers1103 balanced, thus increasing the life of the system.

Communications from rollers 1103 may be passed directly to networkrepeaters or to be passed through mesh networks of rollers 1103 to acommon repeater or to the final destination.

FIG. 12 is a circuit diagram of a wear detector according to anexemplary embodiment. Although the present disclosure is not limited toa specific type of transducer, the use of resistor pairs (redundantresistors) for monitoring is discussed herein as an example. A firstresistor pair T1, having resistors R1 a and R1 b, is embedded nearestthe outer wear surface with a second resistor pair T2, having resistorsR2 a and R2 b, through resistor pair Tn equally spaced along the wearpath. The resistor pair Tn is located closest to the wear limit. When awear surface wears down to a resistor pair, such as R1 a and R1 b, acombinatorial resistance changes. The resistance can be reduced orshorted (if filled with mud) or increased or open (if the connections orresistor are damaged or broken). The change in resistance indicates to aprocessing device 901 that a wear depth corresponding to a particularresistor pair has been reached. Although not shown in FIG. 12, circuittraces may also be made redundant by use of more traces and circuitboard layers to decrease the probability of false indications due tofaulty trace failures.

Redundant transducers and traces improve the monitoring reliability ofthe wear detector. Single component, connection or trace failuresresulting from defects in manufacturing, extremes in temperature, shockor vibration of the operating environment are detected and compensatedfor in the processing circuitry of the processing device 1201. Forexample, if the parallel combination of the resistors R1 a and R1 bequals the value of the resistor R1, then the analog voltage detected atthe processing device 1201 is V/2. If a failure of the resistor R1 a,the resistor R1 b, or a connection or trace path to either of theseresistors results, due to a manufacturing fault, temperature extremes,or from shock or vibration, one of the resistors R1 a or R1 b will beomitted from the circuit. Omission of one of the resistors R1 a or R1 bwill result in the resistance of the resistor R1 being ½ the resistanceof the remaining connected resistor (R1 a or R1 b). The voltage detectedat the processing device 1201 will then be V/3. This voltage level willindicate to the processing device 1201 that the failure may not berelated to wear. If the voltage level is due to wear, it will not make adifference as the other resistor R1 a or R1 b will soon be removed bywear. Until both the resistors R1 a and R1 b in the pair are faulted,the wear-point will not be considered, by the processing device 1201, tohave been reached. In wear detectors that do not have redundancy,failures in any of the traces or transducer will incorrectly indicatethat a wear point was reached. This is an example of direct wearmonitoring.

A conveyor chute wear monitoring system is shown in FIG. 13A andincludes a conveyor chute 1301 with any number of wear pads 1302. Oneembodiment of the chute liner monitoring system is shown as a wear padmodule in the exploded assembly view of FIG. 13B. In this embodiment, awear pad 1302 having a wear surface 1303 and mounting surface 1304 mayhave a printed circuit board (“PCB”) 1305, batteries 1306 and radiofrequency (“RF”) antenna 1307 disposed within. The PCB 1305 iselectrically connected to the RF antenna 1307. The PCB 1305 and RFantenna 1307 are powered by any number of batteries 1306. The PCB 1305may be disposed in a housing 1308 that is disposed in the wear pad 1302and protected by a cover plate 1309. The RF antenna 1307 may be recessedinto the mounting surface 1303 of the wear pad 1302 along with a cover1310 that is made of a material that allows transmission of RF signal topass through the cover 1310. As material is passed through the conveyorchute, the wear pads 1302 decrease in thickness from the wear surface1303. When the end of the wear pad life has been reached, the wearingprocess will have exposed the cover 1310, allowing transmission of theRF antenna 1307 signal from the wear surface 1303. Reception of thesignal by a receiving antenna 1311 indicates that the end of the wearpad life. FIG. 13C is an alternative exploded view of the system of FIG.13B.

FIG. 13D is a wear life monitor using the redundant resistor wear ladderof FIG. 12 embedded in the cover or wear pad 1302. In this embodiment,the RF antenna 1307 is able to transmit from the wear surface 1303throughout the entire life of the wear pad 1302. In this embodiment, theRF antenna 1307 is recessed into the wear surface 1303 and protected bya cover 1310 that is made of a material that allows transmission of RFsignal to pass through the cover 1310. A PCB 1305, batteries 1306 andhousing 1308 are embedded into the mounting surface 1304 of the wear padand protected by a cover plate 1309. The redundant resistor wear ladderis electrically coupled to the PCB 1305. As the wear pad 1302 decreasesin thickness over the wear pad life, the electrical properties of thewear ladder circuit are altered, indicating a certain amount of wear onthe wear pad. This information is processed by the PCB 1305 andtransmitted to a receiving antenna 1311 from the RF antenna 1307. FIG.13E is an alternative view of the system shown in FIG. 13D.

Depending on the embodiment, certain acts, events, or functions of anyof the methods or processes described herein can be performed in adifferent sequence, can be added, merged, or left out altogether (e.g.,not all described acts or events are necessary for the practice of themethods or processes). Moreover, in certain embodiments, acts or eventscan be performed concurrently.

Conditional language used herein, such as, among others, “can,” “might,”“may,” “e.g.,” and the like, unless specifically stated otherwise, orotherwise understood within the context as used, is generally intendedto convey that certain embodiments include, while other embodiments donot include, certain features, elements and/or states. Thus, suchconditional language is not generally intended to imply that features,elements and/or states are in any way required for one or moreembodiments or that one or more embodiments necessarily include logicfor deciding, with or without author input or prompting, whether thesefeatures, elements and/or states are included or are to be performed inany particular embodiment.

While the above detailed description has shown, described, and pointedout novel features as applied to various embodiments, it will beunderstood that various omissions, substitutions, and changes in theform and details of the devices illustrated can be made withoutdeparting from the spirit of the disclosure. As will be recognized, theprocesses described herein can be embodied within a form that does notprovide all of the features and benefits set forth herein, as somefeatures can be used or practiced separately from others. The scope ofprotection is defined by the appended claims rather than by theforegoing description. All changes which come within the meaning andrange of equivalency of the claims are to be embraced within theirscope.

What is claimed is:
 1. A monitoring system, comprising: a fastener; asensor coupled to the fastener; a circuit board electrically coupled tothe sensor; and an antenna electrically coupled to the circuit board. 2.The monitoring system of claim 1, wherein the circuit board is recessedin a cavity in a chassis and the antenna is mounted on the circuitboard.
 3. The monitoring system of claim 2, wherein the circuit board isconductively bonded to a surface of the cavity, thereby extending aground plane of the circuit board into the chassis.
 4. The monitoringsystem of claim 3, wherein the circuit board comprises an annular ringthat is conductively bonded to the surface of the cavity.
 5. Themonitoring system of claim 2, comprising a cover that at least partiallyfills a portion of the cavity in front of the antenna.
 6. The monitoringsystem of claim 1, wherein the fastener is a bolt.
 7. The monitoringsystem of claim 1, wherein the fastener is a nut.
 8. The monitoringsystem of claim 1, wherein the sensor is embedded in the fastener. 9.The monitoring system of claim 4, wherein the fastener has definedtherein a bore; wherein the sensor is disposed in the bore.
 10. Themonitoring system of claim 1, wherein the fastener comprises a washer.11. The monitoring system of claim 10, wherein the circuit board and thesensor are coupled to the washer.
 12. The monitoring system of claim 1,wherein the sensor detects at least one of tension, strain, andvibration.
 13. The monitoring system of claim 1, wherein the antenna isin communication with a wearable device.
 14. The monitoring system ofclaim 1, wherein the sensor is at least one of a vibration sensor, atemperature sensor, an accelerometer, of a strain gauge.